[PATCH] net: phy: Read physical phy IDs before phy is created

[Michal Simek]

ethernet-phy-id directly specify phy ID which is present on the board but
there is no code which really checks that specified phy ID is actually
present on the board. That's why read phy ID regs with get_phy_id() call
and compare it with required ID. If they don't match don't use this driver.

Code is intentionally below reset sequence which get's phy to the right
state and correct address.

Signed-off-by: Michal Simek <michal.simek at amd.com>
---

 drivers/net/phy/ethernet_id.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/ethernet_id.c b/drivers/net/phy/ethernet_id.c
index 8864f99bb32f..7d56ad4aefa7 100644
--- a/drivers/net/phy/ethernet_id.c
+++ b/drivers/net/phy/ethernet_id.c
@@ -18,7 +18,7 @@ struct phy_device *phy_connect_phy_id(struct mii_dev *bus, struct udevice *dev,
 	struct ofnode_phandle_args phandle_args;
 	struct gpio_desc gpio;
 	ofnode node;
-	u32 id, assert, deassert;
+	u32 id, assert, deassert, phy_id = 0xffffffff;
 	u16 vendor, device;
 	int ret;
 
@@ -67,7 +67,21 @@ struct phy_device *phy_connect_phy_id(struct mii_dev *bus, struct udevice *dev,
 		}
 	}
 
-	id =  vendor << 16 | device;
+	ret = get_phy_id(bus, phyaddr, phyaddr, &phy_id);
+	if (ret) {
+		dev_err(dev, "Physical phy is not detected\n");
+		return NULL;
+	}
+
+	id = vendor << 16 | device;
+
+	if (phy_id != id) {
+		dev_err(dev,
+			"Required phyid %08x doesn't match with detected phyid %08x\n",
+			id, phy_id);
+		return NULL;
+	}
+
 	phydev = phy_device_create(bus, phyaddr, id, false);
 	if (phydev)
 		phydev->node = node;
-- 
2.36.1